Bern - The Swiss foreign ministry has expressed its "profound sadness" over an attack on a bus carrying Coptic Christians in central Egypt that has killed at least 28 people and wounded 24 others. The bus was travelling to the Monastery of St Samuel the Confessor, 135 kilometres south of Cairo, from Minya province, when it came under gunfire, Egyptian officials said. No group immediately said it was behind the attack. In a statementexternal link on Friday evening, the Swiss foreign ministry said it "condemned with the strongest terms this bloody attack once again targeting the Egyptian Coptic community". Several children were among the victims, the ministry noted. It expressed its condolences to the families and relatives of the victims. A letter of condolence has been sent to the Egyptian president, Abdel Fattah el-Sisi, the ministry added. This latest attack follows two suicide bombings at Palm Sunday services at churches in Egypt on April 9, that left 46 people dead. Islamic State (IS) claimed responsibility for this and an attack on a church in the capital in December which killed 29 people. In February a Christian community was forced to flee the northern Sinai peninsula after a series of gun attacks. Copts make up about 10% of Egypt's population of 92 million.